1. Field of the Invention
This invention relates to the conversion of liquid organic materials to suitable products by means of catalytic distillation. More particularly, it relates to an improved catalyst-packing material for use in catalytic distillation and to the processes using such catalyst-packing material.
2. Description of Prior Art
It is known that some reactions may be carried out by means of catalytic distillation. In catalytic distillation, reaction and separation are carried out simultaneously in a distillation column.
In U.S. Pat. No. 4,215,011, Smith, Jr, discloses a method for the separation of an isoolefin, preferably having four to six carbon atoms, from streams containing mixtures thereof with the corresponding normal olefin, wherein the mixture is fed into a reaction-distillation column containing a fixed-bed, acidic cation exchange resin and contacted with the acidic cation exchange resin to react the isoolefin with itself to form a dimer and the dimer is separated from the normal olefin, the particulate catalytic material, i.e., the acidic cation exchange resin, being contained in a plurality of closed cloth pockets, which pockets are arranged and supported in the column by wire mesh.
In U.S. Pat. No. 4,443,559, Smith, Jr, discloses a catalytic distillation structure which comprises a catalyst component associated intimately with or surrounded by a resilient component, which component is comprised of at least 70 vol % open space for providing a matrix of substantially open space. Examples of such resilient component are open-mesh, knitted, stainless wire (demister wire or an expanded aluminum); open-mesh, knitted, polymeric filaments of nylon, Teflon, etc; and highly-open structure foamed material (reticulated polyurethane).
It has been shown by Patil, et al, in a paper given in ACS Symposium Series No. 368 in Toronto, Ontario, Canada Jun. 5-11, 1988) and printed in ACS Symposium Series No. 368, PERSPECTIVES IN MOLECULAR SIEVE SCIENCE, Flank and Whyte, Jr, Editors (1988), American Chemical Society, that a cordierite ceramic honeycomb washcoated with silicate is a suitable catalyst for methanol conversion. Patil, et al, pointed out that an active zeolite catalyst may be washcoated on ceramic honeycomb substrates and that such technique has been used widely in automotive emissions control, woodstove combustors, control of volatile organic emissions from organic solvents, ozone abatement in jet aircraft passenger cabins, and NO.sub.x abatement from industrial emissions. Patil, et al, noted the lack of exploitation of washcoats of zeolite catalysts in the chemical process industries.
Now it has been found that a rigid, cellular monolith or a coated, rigid, cellular monolith can be used suitably as the catalyst-packing material in processes involving catalytic distillation.